CVE-2023-44196 in Junos OS Evolved
Summary
by MITRE • 10/25/2023
An Improper Check for Unusual or Exceptional Conditions in the Packet Forwarding Engine (pfe) of Juniper Networks Junos OS Evolved on PTX10003 Series allows an unauthenticated adjacent attacker to cause an impact to the integrity of the system.
When specific transit MPLS packets are received by the PFE, these packets are internally forwarded to the RE. This issue is a prerequisite for CVE-2023-44195.
This issue affects Juniper Networks Junos OS Evolved:
* All versions prior to 20.4R3-S8-EVO; * 21.1-EVO version 21.1R1-EVO and later; * 21.2-EVO versions prior to 21.2R3-S6-EVO; * 21.3-EVO version 21.3R1-EVO and later; * 21.4-EVO versions prior to 21.4R3-S3-EVO; * 22.1-EVO versions prior to 22.1R3-S4-EVO; * 22.2-EVO versions prior to 22.2R3-S3-EVO; * 22.3-EVO versions prior to 22.3R2-S2-EVO, 22.3R3-EVO; * 22.4-EVO versions prior to 22.4R2-EVO.
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Analysis
by VulDB Data Team • 10/25/2023
The vulnerability described in CVE-2023-44196 represents a critical flaw in the Packet Forwarding Engine (PFE) component of Juniper Networks Junos OS Evolved operating on PTX10003 Series devices. This issue manifests as an improper check for unusual or exceptional conditions, creating a pathway for unauthenticated adjacent attackers to compromise system integrity. The vulnerability operates at the network layer where specific transit MPLS packets trigger internal forwarding mechanisms that ultimately reach the Routing Engine (RE), making it a significant concern for network infrastructure security. The flaw is particularly dangerous because it allows an attacker to manipulate packet processing flows without requiring authentication credentials, leveraging physical proximity to the device as the attack vector. This type of vulnerability falls under the CWE-707 category of "Improper Check for Unusual or Exceptional Conditions," which is classified as a weakness that can lead to system instability and potential denial of service conditions.
The technical implementation of this vulnerability involves the PFE's handling of transit MPLS packets that are received and subsequently forwarded to the RE component. When these specific packet patterns are processed, they trigger an abnormal condition within the PFE's packet handling logic that was not properly accounted for in the software's error handling mechanisms. The affected versions span multiple release branches of Junos OS Evolved, indicating a widespread issue that affects various software releases across different years of development. The vulnerability is particularly concerning because it requires minimal attack prerequisites and can be exploited by an adjacent attacker who has physical access to the network device, making it a significant risk in environments where such access might be possible. The relationship to CVE-2023-44195 demonstrates that this vulnerability serves as a prerequisite for a broader attack chain, suggesting that exploitation of this flaw could enable more severe consequences.
The operational impact of CVE-2023-44196 extends beyond simple service disruption to potentially compromise the integrity of the entire system. An attacker who successfully exploits this vulnerability can cause the PFE to process packets in unexpected ways, potentially leading to system instability, crashes, or even complete system failure. The integrity compromise means that the attacker could manipulate how packets are forwarded through the network, potentially redirecting traffic or creating blind spots in network monitoring. This vulnerability is particularly dangerous in carrier-grade networks where PTX10003 Series devices serve as core infrastructure components, as it could allow an attacker to disrupt routing operations or create unauthorized traffic paths. The fact that this affects multiple version ranges indicates that Juniper Networks has been working on addressing this issue across various software releases, but the vulnerability has persisted across several development cycles.
Mitigation strategies for CVE-2023-44196 should focus on immediate software updates to patched versions of Junos OS Evolved that address the improper check for unusual conditions in the PFE. Organizations should prioritize upgrading all affected devices to the latest stable releases that contain the necessary security patches, particularly given the unauthenticated nature of the attack vector. Network administrators should also implement additional monitoring and logging mechanisms to detect abnormal packet processing patterns that might indicate exploitation attempts. Physical security measures should be reinforced around affected devices to prevent unauthorized adjacent access, as this vulnerability specifically targets attackers who can physically approach the network infrastructure. The ATT&CK framework classification for this vulnerability would include techniques related to privilege escalation and system compromise through network infrastructure manipulation. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of any successful exploitation attempts, as the vulnerability affects core routing functionality that could be leveraged to gain broader network access. Regular security assessments and vulnerability scanning should be conducted to identify any remaining unpatched systems within the network infrastructure that might be susceptible to similar attacks.